1 12 Roof Slopes

The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7.

1 12 roof slopes.

Roof slopes are most commonly defined by the rise over run ratio. What exactly is roof slope. Arctan 3 12 14 0 the primary purpose of pitching a roof is to redirect water and snow. In degrees 10 2 in 12 or 1 in 6 is considered a minimum.

Some sources consider low slope to include 3 12 pitch roofs. Simply locate a roof rafter board place the end of the level against the bottom edge and measure from the 12 inch mark vertically to the bottom edge of the rafter. Metal roof panels should be installed on roof slopes according to particular seams 2015 irc r905 10 2. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

Definitions vary on when a roof is considered pitched. Also if clay and concrete roof tiles are installed on a roof slope of 2 1 2 12 to 4 12 it shall be provided with a double underlayment application. If a roof rises 1 in a length of 12 this is 1 12 roof pitch. I e 4 inches of rise per 12 inches one foot of run.

If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks. The exact roof slope in degrees is given by the arctangent. Slopes greater than 18 12 are found on a frame roofs and some mansard style. Clay and concrete roof tiles can only be installed on roof slopes of 2 1 2 12 or greater.

See low slope roofing. Most roof s have a pitch in the 4 12 to 9 12 range. Then you ll be able to measure slope from an unfinished attic space under the roof. Low slope roofs are from 0 to 3 12 in pitch.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof. Thus pitch is typically greater in areas of high rain or snowfall. Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level.

1 12 roof pitch angle 4 76 degrees.